This book presents principles of animal biodiversity, its importance, sustainable utilization, and conservation. The introductory chapter explores the origins and evolution of biodiversity throughout time, shedding light on the remarkable developments that have taken place over the ages. The subsequent chapters of the book reveal the tools and techniques used to assess the status of biodiversity at any given stage. The book meticulously details the indicators and measurement methods employed to gauge the health and vitality of biodiversity. Furthermore, it elucidates the vital role biodiversity plays in serving humanity and underscores the dire consequences that may ensue if we fail to preserve it. It also introduces the nomenclature of species and explores their intricate phylogenetic relationships with both living and non-living entities. The spatial and temporal distribution of animals, unraveling the fascinating patterns and dynamics that govern their presence across the globe, is also discussed in the book. Additionally, the book unveils a repertoire of conservation methods aimed at preserving existing biodiversity and ensuring its sustainable future. Toward the end, the book offers valuable suggestions and highlights untapped avenues for future research, all geared toward safeguarding the current level of biodiversity and ensuring its prosperity in the years to come. This book is a valuable source for students and professionals in the fields of biology, ecology, and conservation biology.